In which of the following algae, motile colonies are found ?

Options

A. Volvox
B. Spirogyra
C. Ulothrix
D. All of the above

Answer

To solve the question "In which of the following algae, motile colonies are found?" we will analyze the options provided: Volvox, Spirogyra, Lotrix, and all of the above.

### Step-by-Step Solution:

1. **Understanding Algae**:
- Algae are simple, chlorophyll-bearing organisms that are primarily aquatic and can be found in both freshwater and marine environments. They are autotrophic, meaning they can produce their own food through photosynthesis.

2. **Types of Algae**:
- Algae can vary significantly in form and size. They can be classified into different categories based on their structure:
- **Colloidal Algae**: These algae form colonies.
- **Filamentous Algae**: These algae form long, thread-like structures.

3. **Analyzing the Options**:
- **Volvox**: This is a type of green algae that forms motile colonies. Each colony consists of numerous cells that can move together, making them motile.
- **Spirogyra**: This is a filamentous green algae that does not form colonies. Instead, it exists as long, unbranched filaments.
- **Lotrix**: Similar to Spirogyra, Lotrix is also filamentous and does not form colonies.

4. **Conclusion**:
- Among the options provided, only **Volvox** is known for forming motile colonies. Therefore, the correct answer is **Volvox**.

### Final Answer:
**Volvox**